title: Water absorption dependent photoconductivity of a freestanding polymer bridge.
abstract: The photo-response of a freestanding constricted polymeric solid-state bridge of water soluble sodium poly[2-(3-thienyl)-ethoxy-4-butylsulfonate] (SPTEBS) was studied as a function of water vapor pressure. The dark current dramatically increases with water vapor pressure higher than 12 Torr. Surprisingly, under light illumination, the short-circuit current of the polymeric solid-state bridge decreases with increasing water vapor pressure so that, above 12 Torr of water vapor pressure, the short-circuit current under the light illumination is even lower than the dark current. This negative photo-response of the polymeric solid-state bridge is attributed to the self-doping by hydration of the polymer and the de-doping, possibly the result of photo-induced desorption of adsorbed water molecules.
authors.affiliation: Department of Electrical Engineering, Korea Army Academy, Yeong-Cheon, Kyoungbuk 770-849, Korea.
authors.forename: Daeyoung
authors.initials: D
authors.lastname: Kim
authors.forename: Jaewu
authors.initials: J
authors.lastname: Choi
mesh_terms: D000327:Adsorption; D003300:Copper / Q000737:chemistry; D006046:Gold / Q000737:chemistry; D006813:Humidity; D008027:Light; D008956:Models, Chemical; D010777:Photochemistry / Q000379:methods*; D011108:Polymers / Q000737:chemistry*; D013696:Temperature; D014867:Water / Q000737:chemistry*
chemical_list: D011108:Polymers; D014867:Water; D006046:Gold; D003300:Copper